Prognostic significance of vascular dilation and tortuosity insufficient for plus disease in retinopathy of prematurity.

Background: Plus disease, one of the most important prognostic indicators in retinopathy of prematurity (ROP), is designated as present or absent. A grading system based on comparison with standard, high-quality color photographs may be useful to more accurately describe the spectrum of vascular dilation and tortuosity preceding plus disease, but it is of practical value only if it has prognostic significance. We hypothesized that grading of "pre-plus" vascular changes can identify eyes at risk for progression to vision-threatening ROP.

Methods: Video clips of posterior pole images captured at the examination closest to 33 weeks' postconceptional age of 32 infants screened during an 18-month period were randomized. Two masked examiners viewed and graded the images in comparison with standard photographs representative of 5 distinct grades of retinal vascular dilation and tortuosity. A case-control design was used to compare the incidence of progression to stage 3 ROP, development of plus disease, and requirement of laser treatment between infants with normal posterior poles and those judged to have early dilation and tortuosity insufficient for plus disease.

Results: Of the 8 patients with mild vascular dilation and tortuosity insufficient for plus disease, 5 (63%) eventually required laser treatment, 4 (50%) later developed stage 3 ROP, and 5 (63%) progressed to plus disease. Of the 24 patients with normal posterior poles, none required laser treatment, 2 (8%) developed stage 3 ROP, and none progressed to plus disease. The group with mild vascular dilation and tortuosity had a significantly higher incidence of progression to laser treatment (P =.0003), stage 3 ROP (P =.027), and plus disease (P =.0003).

Conclusions: Early vascular dilation and tortuosity judged insufficient for plus disease have prognostic significance in the early course of ROP. A grading system that uses standard, high-quality color photographs representing the spectrum of "pre-plus" vascular changes has potential utility in both the clinical and research settings.